Convection heat exchangers in which a fluid circulates around a solid, for example inside a tube, and in which, given the existence of a temperature difference between both, a heat exchange takes place, are known.
In particular heat exchangers in which a tube through which a cooling liquid circulates is arranged on a metal sheet are known. Such exchangers are used, for example, in cooling appliances, freezers, boilers, etc. The tube is generally arranged on the largest possible surface of the metal sheet to improve the heat exchange, so it is usually necessary to bend the tube so that it has the same shape as the sheet on which it is going to be fixed, as shown for example in U.S. Pat. No. 2,386,889A. To that end, the tube can be bent on one side and the sheet on the other, and the tube can be fixed to the sheet after bending. Another option is to fix the tube to the sheet and bend them together. It is known that bending the tube and the sheet together can cause the crushing of the tube, which is not convenient because it would limit circulation of the cooling liquid. Bending the tube and the sheet together is also known to cause marks on the sheet, damaging it.
Documents U.S. Pat. No. 1,987,422A and GB438267A describe a method for making heat exchangers. Said method comprises the following steps: a step in which a conduit is placed on a metal sheet, a step in which said conduit is fixed to the sheet through cleats, said cleats allowing the conduit to slide under the same, and a step in which the unit formed by the sheet and the conduit is bent, sliding the conduit with respect to the sheet such that the radius of curvature of the conduit is substantially greater than that of the sheet.
Document U.S. Pat. No. 2,625,378A discloses a heat exchange comprising a metal sheet, a metal exchange tube supported on said sheet, and fastening means for fastening the tube to the sheet, said heat exchange being bent with respect to at least one bend line and the fastening means comprising a cover covering almost the entire length of the tube, said cover being fixed to the sheet by means of adhesive.